Deposition in chemistry refers to the process in which a gas changes directly to a solid without going through the liquid state. It is a thermodynamic process and is the reverse of sublimation). Deposition can be viewed as a reverse process to dissolution or particle re-entrainment). Some examples of deposition in nature include frost forming on the ground and cirrus clouds forming high in the atmosphere. Deposition releases energy and is an exothermic phase change).

In addition to its natural occurrences, deposition is also used in industrial processes such as evaporative deposition, which involves heating a solid material to the gaseous state in a low-pressure chamber, allowing the gas molecules to travel across the chamber space and then deposit to the solid state on a target surface, forming a smooth and thin layer on the target surface).

Overall, deposition is an important process in chemistry and has various applications in both natural and industrial settings.